Which of the following applications require best-effort (unpredictable and un-reliable), guaranteed (predictable and reliable, with accountability), or predictable service. Give reasons for your choices. a. High-quality (phone company-grade) voice calls

b. Voice over IP (VoIP) calls

c. A commercial Video-on-Demand service

d. User access to servers in a corporation

Explain briefly why you cannot expect to find a previous version of every file with which you work.

Write a modular program (no classes yet, just from what you learned last year), that allows two players to play a game of tic-tac-toe. use a two-dimensional char array with 3 rows and 3 columns as the game board. each element of the array should be initialized with an asterisk (*). the program should display the initial board configuration and then start a loop that does the following: allow player 1 to select a location on the board for an x by entering a row and column number. then redisplay the board with an x replacing the * in the chosen location. if there is no winner yet and the board is not yet full, allow player 2 to select a location on the board for an o by entering a row and column number. then redisplay the board with an o replacing the * in the chosen location. the loop should continue until a player has won or a tie has occurred, then display a message indicating who won, or reporting that a tie occurred. player 1 wins when there are three xs in a row, a column, or a diagonal on the game board. player 2 wins when there are three ox in a row, a column, or a diagonal on the game board. a tie occurs when all of the locations on the board are full, but there is no winner. input validation: only allow legal moves to be entered. the row must be 1, 2, or 3. the column must be 1, 2 3. the (row, column) position entered must currently be empty (i.e., still have an asterisk in it).

Aspeed limit sign that says "night" indicates the legal speed between sunset and sunrise.